trying to diagnose a boost issue with a freshly rebuilt engine, tough to do so when my tach is not working. can anyone tell me where the sending unit for the tach goes to? or why it would be pinned at 9K+. I replaced the instument cluster during the rebuild, every other guage works great. on the first start the tach fluctuated up and pinned itself at 9k+

 

still tyring to figure this out. anyone have any ideas?